Selective plating of printed circuit boards

Abstract

An improved plating method in which non-plated vias or through holes are temporarily metalized for use as busses during selective noble metal plating and subsequently de-metalized to prevent shorting together of the nobly plated features.

What is claimed is:  
     
         1 . A multi-layered semiconductor device comprising at least two features, each feature being electroplated with a noble metal, and each electroplated feature being coupled to one of at least two conductors embedded within the mutli-layered semiconductor device, wherein the at least two conductors are electrically isolated from each other and intersect a common non-plated via or through hole.  
     
     
         2 . The multi-layered semiconductor device of  claim 1  wherein the multi-layered semiconductor device is a printed wiring board (PWB) and each of the electroplated features is a via or through hole.  
     
     
         3 . The PWB of  claim 2  further comprising a fastener received by the non-plated via or through hole, the fastener being either non-conductive or electrically disconnected from the at least two conductors.  
     
     
         4 . A method of plating comprising: 
 providing a device having a plurality of features to be selectively plated wherein each of the plurality of features to be selectively plated is electrically coupled to a metalized via or through hole;    selectively plating the plurality of features to be plated;    converting the metalized via or through hole to a non-metalized via or through hole.    
     
     
         5 . The method of  claim 4  wherein converting the metalized via or through hole comprises etching the via or through hole to remove the metalization.  
     
     
         6 . The method of  claim 4  wherein converting the metalized via or through hole comprises drilling the via or through hole to remove the metalization.  
     
     
         7 . The method of  claim 4  further comprising inserting a fastener into the non-metalized via or through hole.  
     
     
         8 . A method of selectively plating features of a printed wiring board (PWB) formed in accordance with a PWB design, the PWB having at least one portion adapted to be coupled to a current source during electroplating, the method comprising: 
 using the PWB design to identify features of the PWB which are to be selectively plated, but which will be electrically isolated from the at least one portion of the PWB adapted to be coupled to a current source during electroplating;    using the PWB design to identify non-plated through holes which will be used as temporary busses during plating;    modifying the PWB design by adding conductors that will electrically connect the identified features to be plated with the temporary busses;    providing a PWB that at least partially corresponds to the PWB design by including the identified features, identified through holes, and added conductors;    forming the temporary busses out of the identified through holes;    selectively plating the identified features; and    electrically isolating at least some of the added conductors from each other after selective plating is complete.    
     
     
         9 . The method of  claim 8  wherein the step of using the PWB design to identify non-plated through holes which will be used as temporary busses during plating follows a step of modifying the PWB design by adding at least one non-plated through hole that will be used as a temporary bus during plating, the at least one added through hole being one of the identified non-plated through holes.  
     
     
         10 . The method of  claim 8  further comprising modifying the PWB design by adding conductors which will electrically connect the temporary busses to a current source during plating.  
     
     
         11 . The method of  claim 8  wherein the step of forming the temporary busses comprises temporarily plating the walls of the identified through holes.  
     
     
         12 . The method of  claim 8  wherein the step of forming the temporary busses comprises temporarily filling the identified through holes with an electrically conductive material.  
     
     
         13 . The method of  claim 8  wherein the step of electrically isolating at least some of the added conductors from each other after selective plating is complete comprises removing conductive material from at least one of the temporary busses.  
     
     
         14 . The method of  claim 13  wherein removing conductive material from at least one of the temporary busses is accomplished by drilling or etching.